Sound-producer



C. l. ROHLAND.

SOUND PRODUCER.

APPLICATION map JAN- 11. 1916- RENEWED JULY 16, 1919.

1,321,336. Patented N 0v. 11, 1919.

2 SHEET;SH.EET I.

y 2 4 5 Z 5 11311111" ii 1 C. l. ROHLAND.

SOUND PRODUCER. APPLlCATlON FILED lAN.l7.1916. RENEWED JULY 16. 1919.

1 3 2 1 3 3 6 v Patented Nov. 11, 1919.

2 SHEETS-SHEET 2.

CUBE J. ROHLAND, 0F WORCESTER,

DELAWARE- MASSACHUSETT'S, ASSIGN'OB, MENTS, T0 KLAXON COMPANY, OFNEWARK, NEW JERSEY,

BY MESNE ASSIGN- .A CORPORATION OF SOUND-PRODUCER.

Application filed. January 17, 1916,

To all whom it may concern:

Be it known that 1, Cum J. ROHLAND, a citizen of the German Empire, anda resident of \Vorcester, in the county of Worcester and State ofMassachusetts, have invented certain new and useful Improvements inSound-Producers, of which the following is a specification.

This invention relates to improvements in sound producers, andespecially to electromagnetic horns, and the main object of theinvention is to provide an improved and simple article of this kind inwhich a very much louder sound can be produced with a given currentconsumption than in devices of this kind heretofore used.

One of the principal features of the invention is the provision ofa hornhaving a pair of diaphragms both of which are adapted to be set invibration at the same time, so that the sound emitted by the horn willbe that produced by the vibration of a plurality of diaphragmssubstantially in unison.

Another important feature of the invention is to provide a horn having adiaphragm operated by an electromagnetic or other suitable tapper orfloating vibrator, in which the diaphragm is driven in one directionpositively by the tapper and on its return movement imparts a returnstroke to said tapper, the diaphragm being sufiiciently resilient, andbeing associated with the tapper, to permit it to be used in thismanner, instead of employing a separate spring for the purpose as hasbeen the custom heretofore. 4 1

A horn having a plurality of separate diaphragms adapted to be set invibration substantially simultaneously may be readily converted into aduplex or multiplex horn having a plurality of bell-mouths facing invarious directions and hence capable of projecting the sound produced incorresponding directions; and an important feature of my invention isthe provision of such a horn, particularly one in which a commonactuating means is employed for setting the different diaphragms invibration and in which all the movablev parts are completely inclosedand out of the way.

other features of my present invention not hereinbefore referred to willbe hereinafter described and claimed and are illus- Specification ofLetters Patent.

Patented Nov. 11, 1919.

Serial No. 72/201. Renewed July 16, 1919. Serial No. 311,382.

trated in the accompanying drawings, in which- Figure 1 is asubstantially central longitudinal section and elevation of a singlehorn particularly adapted for use with alternating current.

' Fig. 2 is an end elevation of the same with parts removed, lookingfrom the right in Fig. 1.

Fig. 3 is a detail illustrating in elevation and section theelectromagnetic operating means for setting the diaphragms invvibration.

Fig. 4 is a longitudinal section, similar to Fig. 1, of a duplex horn ofthe alternating current type.

Fig. 5 is a similar view on a smaller scale of a direct current horn.

Fig. 6 is a diagram showing the circuit of the direct current horn.

Similar characters designate like parts in all the figures of thedrawings.

Referring first to Figs. 13 inclusive, in which I have illustrated mypresent invention as embodied specifically in an alternating currenthorn,'2 designates the usual flaring bell-mouth of such a horn, near thesmall end of which will be placed a diaphragm or diaphragms adapted tobeset in vibration by suitable means. In Fig. 1 two diaphragms are shown,at 3 and 4, and these are separated a suflicient distance to permit theoperating means associated with each diaphragm to be placed betweenthem. The operating means illustrated is common to both diaphragms, thatis to say, it is adapted to set both diaphragms in vibration practicallysimultaneously and thus ob shell 5, said diaphragms tainthe additionaleffect due to the vibration of the ends of this shell and form with it.a

completely inclosed chamber within which .the operating mechanismwill'be contained.

This operating means may be of any suitable type, but I prefer to employelectromagnetic means phragm preferably removable as a whole from thecasing, and is shown as embodying abracket, 6, for, supporting theelectromagnet and other parts. An electro=magnet, 7. of the forvibrating each dia-" This electromagnetic means is.

duplex type is mounted on said bracket. The armature of this magnet isshown as a circular disk, 8, free to turn about its axis in a rod, 9,which constitutes the main ele ment of the means for setting eachdiaphragm in vibration. This rod is free to move back and forth with thearmature, 8 in a path substantially perpendicular to the diaphragms 3and l at the centers thereof. The length of the rod may be adjustedslightly as may be desired by a pair of screws, 9, at opposite endsthereof. The diaphragm 3 is shown asheld in place between two clampingrings one of which is fixed and is formed by a flanged portion, 5, ofthe cylindrical shell 5 and the other of which is formed by theperipheral portion of a removable end plate, 10. The diaphragm isintended to be held at its periphery only between these rings, it beingshown as resting upon a narrow pin of the flange 5' and as secured inplace by fastening devices such as rivets 11, passing through the parts.The inner face of one or both of the surfaces engaging the oppositesides of the diaphragm will preferably be so formed as to permitthe'diaphragm to vibrate with as large a free area as possible. At theopposite end of the casing the diaphragm 4 is similarly held in lacebetween a narrow rim of a flange, d of the shell 5 and a separateannulus, 12, having feet, 12', or any other suitable supporting means,fastening devices, such as rivets 11, being shown for holding the partstogether.

Suitable means will also be provided for varying the tension on one orboth diaphragms for the purpose of varying the sound produced by thevibration thereof. Similar devices are preferably applied to bothdiaphragms. In the construction shown thumb-screws, 14, with milledheads cooperate with locking springs, 14, by means of which any desiredadjustment is maintained. One or more of these thumbscrews may bepressed against each diaphragm for the purpose of increasing ordecreasing the tension on the same by bending said diaphragm toward theoperating means or permitting it to withdraw therefrom. A circle ofthese adjusting thumb-screws is shown in the drawings. The adjustment ofeach diaphragm may be within the limits of movement thereof and thesound produced will be correspondingly varied.

In the operation of the horn shown in Figs. 1-3 when the magnet isenergized and its armature attracted the vibrator will be forced towardone of the diaphragms (in the construction shown the diaphragm 4) andwill displace this resilient diaphragm outwardly. IVhen the magnet isdeiincrgized the return movement of this resilient vibratory diaphragmwill return the rod 9 varied as desiredmenace and the armature of themagnet to the opposite end of their range of movement, said diaphragmserving as a spring to impart this return stroke to these parts. Thereturn stroke of the tapper of course displaces the other diaphragmoutwardly, and thus starts it also in vibration. The next impulse of thealternating current will start another sequence of operations. As thealternating current impulses follow one another in quick succession thetwo diaphragms will be put in rapid vibration practicallyinstantaneously and will continue to vibrate until the current isinterrupted.

'In Fig. 4 I have illustrated a modification of the invention in whichthe device has a plurality of bell-mouths and is so constructed as to beadapted for suspension from a ceiling or other suitable point of supportand to project sounds in various di rections. In most respects this hornis similar to that shown in Fig. 1, it having a similar bell-mouth, 2*,and diaphragms, 3 and 4 between which is located operating means, hereshown as mounted on a bracket, 6, and embodying an electro-magnet, 7 anarmature, 8 and a tapper, 9 similar to the corresponding parts shown inFig. 1. These parts are mounted in a casing 0r shell, 5, and thediaphragms close the ends of the casing at points adjacent to the smallend of the bell-mouth Wand of another bell-mouth, 2 which is placedopposite the bell-mouth 2 and takes the place of the support shown inFig. 1. The means for holding and fastening the diaphragms are or may besubstantially similar to the means previously described in connectionwith Fig. 1, two end plates 10 and 10 having suitable fastening meansbeing illustrated. The adjusting 105 means for the diaphragms is alsoshown as similar to that in Fig. 1. It will be obvious, of course, thatthe adjustment at one side of the duplex horn illustrated may bedifferent from that at the other, which per- 110 mits different soundsto be projected from the different mouths of the horn. The shell 5differs from that shown at 5 in having a boss, 5 with a threaded openingto receive the end of a threaded tube or pipe, 15, by 115 means of whichthe device as a whole may be suspended from a ceiling or other point.The tube 15 also serves to inclose the wires leading to theeleotro-magnet 7"; and hence all of the main parts are completely 120inclosed and protected. By means of a construction such as justdescribed a multiple horn is formed having a plurality of bellmouthsone. for each diaphragm adapted to project sound in various directionsas de- 125 sired.

In Figs. 5 and 61 have illustrated another modification of the inventionin which the elcctro-magnetic operating means is somewhat different,from that shown inFig. 1 in 130 order to adapt it to be used with directourrent. Here the electromagnet 7 serves to operate an interrupter, 16,of any suitable type one element of which is shown as connected with thetapping means operated by the armature and as movable therewith. Theinterrupter illustrated comprises as its main parts two contact-armsconnected respectively by conductors, 17 and 18, with the mainconductors, 19 and 20 of the circuit in which the electromagnet 7 isconnected, a suitable resistance coil being shown in shunt, at 21, forreducing sparking at the terminals of the interrupter. One of thecontact arms extends past the other so as to engage the plunger 9 and beactuated by it. The device 16 operates in substantially the same manneras the corresponding devices employed in connection with electric. bellsand for analogous uses. Normally the two contactarms of the interrupter16 are ihengagement. -When the magnet is energized these contacts areseparated by the motion of the plunger and hence the circuit of themagnet 7 is interrupted. This action is, of course,

rapidly repeated with the result that there is the usual rapid make andbreak of the circuit of the magnet and a corresponding movement of itsarmature. The efiect of the energization and deenergization of the magnet on the vibrating means is substantially the same as previouslydescribed in connection with the other views.

My improved horn may of course be used for any purpose for which such adevice is adapted, as in signal systems, on motor cars, etc. Theelectromagnet employed in any particular type of horn may also, ofcourse, be of any well known or suitable type. With a structure such asdescribed, having few parts and having an additional diaphragm forincreasing the volume of the sound, I have found that I can operate thehorn with current of much lower amperage than is used in other horns andproduce louder sounds with much less current.

Although I have illustrated and described certain forms of theinvention, I am aware of the fact that the same can be carried out inother forms without departing from the scope thereof as expressed in theclaims. Therefore I do not wish to be limited to all the details ofconstruction herein shown and described. but

What I claim is:

1. In a horn, the combination of a resiliout diaphragm. an clectromagnetarranged with its axis perpendicular thereto, a floating vibrator fixedto the armature of said magnet and perpendicular to said diaphragm, theelectromagnet being arranged to draw the end of said vibrator in onedirection and then release it, the diaphragm constituting means forforcing the vibrator away, and a second diaphragm in position phragm.

to be vibrated by the other end of the vibrator.

2. In a sound producer, the combination of a resilient diaphragm, anelectromagnet arranged with its armature adjacent thereto, a floatingvibrator movable with the armature of said magnet toward and. from thediaphragm, the electromagnetbeing located in a position to draw the endof said vibrator in one direction and then release it, and the diaphragmconstitutingthe sole means for forcing the vibrator away, and a seconddiaphragm in position to be vibrated by the other end of the vibrator.

3. A horn, comprising a pair of separated" diaphragms, andelectromagnetic means located between said diaphragms and including avibrator and an electromagnetic coil, both substantially perpendicularto the diaphragms for setting said diaphragms in vibration, saidvibrator being mounted entirely free from all fixed elements of thehorn.

A. A horn, comprising a tapper for starting the vibration of adlaphragm, a resilient diaphragm movable in one direction under theinfluence of the working stroke of said tapper and constituting the solemeans for imparting a return stroke to said tapper, and means foroperating said tapper comprising an electromagnet having a freelymovable armature on the side opposite said diaphragm and fixed withrespect to said tapper so as to move therewith.

5. A horn, comprising a diaphragm, means for supporting said diaphragmat its periphery, means for varying the tension .on said diaphragm saidmeans including an Y with said milled head, and means for vibrating saiddiaphragm.

6. A sound producer, comprising a diaphragm, means for supporting saiddiaphragm at its periphery, means for varying the tension on saiddiaphragm said means including a circle of adjusting screws eachcooperative with said diaphragm at a ferent point in the peripherythereof, and means forvibrating said diaphragm.

7. A horn comprising a pair of separated substantially paralleldiaphragms, a rod disposed therebetween and substantially at rightangles to each and unattached thereto, and an alternating currentelectromagnct for effecting longitudinal movement of said rod in onedirection to vibrate one of said diaphragms, said diaphragm acting toeiIec-t longitudinal movement of said rod in the opposite directiontoyibrate the other dia- 8. A horn comprising a pair of separatedsubstantially parallel dlaphragms, a rod disposed therebetween andsubstantially at difright angles to each andunattached thereto, and analternating current electromagnet having its armature secured to saidrod and having coils upon opposite sides of said rod with their aXessubstantially parallel to the latter, said rod acting upon one of saiddiaphragms by the attraction of said armature, and said diaphragmserving to return said rod and armature to act on the other diaphragmduring the alternation of the current.

9. A horn comprising a pair of separated substantially paralleld-iaphragms, a rod therebetween and substantially at right angles toeach and unattached thereto, an alternating current electromagnet foreffecting longitudinal movement of said rod in the direction of onediaphragm, said diaphragm serving to return the rod in the direction ofthe other, and means for varying the effective length of said rod inrespect to the distance between said diaphragms.

Signed at Worcester i the county of Worcester and State oflhassachusetts this 5th day of January A. D., 1916.

"' CURT J. ROHLAND.

